Follow-up tweet: Nield: commercial crew companies heading down the home stretch, although launch dates for test flights remain under review. More parachute tests needed since models used by parachute community may not accurately model loads.

Its interesting in that we use to use parachutes a lot in the Apollo days, they worked, though we could not then model exactly how/why they worked. Now NASA wants accurate models as to them working (or not working). It would be interesting to see if the Apollo design would have passed such a criteria.

This is partially correct. Fuel and oxidizer being vented during the descent is believed to have been the cause. This was a planned venting of the remaining fuel and oxidizer that was left in the tanks prior to landing.

PDF of the Apollo 15 report. Page 180 covers the parachute failure and suspected causes. The venting oxidizer was ruled as the most likely cause as it was venting at the time of the failure.

Unfortunately not. It is also often a sim structure issue as the FEA mesh may not line up with the CFD mesh and everytime the structure changes shape you need to recalculate the CFD mesh. It can introduce discontinuities in the flow which don't exist in reality.

I saw in a video that SpaceX do have a pretty spiffy adaptive mesh system but I don't think it's intended for aeroelasticity. It's trying to track combustion as it shifts and the movement of shockwave boundaries as they shift during flight.

Certian level of modeling you can do to the error limit of manufacturing. I mean, the math guys have got to keep at this stuff if we are ever going to get a scramjet to stay lit, but in this era of 3dl molded sails and hydrofoil sailboats, the full scale test model throws some shockwaves into the billions of assumptions that go into even the best models. In perfect conditions, those fancy rigs are awesome (for a price) but we have 200 year old rule of thumb engineering that meets the variability of the real world better when talking about blue water sailing.

That is just a goofy way of stating the fact that we still have issues modeling rigid objects in a fluid. Figuring out what all happens to a stretchy bit of stitched springy fabric flying down a hurricane of its own making is not going to happen within a few million test iterations. Binary computers themselves operate in a framework that limits how they model stuff of that complexity. Not sure how useful models that simulate behavior even at the thread/fiber level or interactions with water vapor variability would ever really get you past even one iteration of actual testing. Just some jaw cracking stuff to try to model. Might be every bit as hard as anything you find in climate or planetary science, despite the smaller seeming scope. Good thing we can just build it and see what happens.

Magitech pop-science quantum computers, maybe. But it's still an active research question as to if there is any algorithm that can run on an existent or designed quantum computer that cannot also be run on a classical computer with at most a polynomial runtime penalty. (In short - we don't know of any problems that are actually faster on the kinds of quantum computers that we know how to build)

I met Adam a few times, who is one of the two authors on that. Friend of a friend. Crazy genius. Helps that he worked for Nvidia and invented all these modeling techniques down to the binary and the way it interacts with individual graphics card components. Were these techniques to be fully utilized, it’d bump fluid modeling up a full order of magnitude (or the time/pier to model down an order). Crazy what one person can do. And the impact of that can spread across virtually every industry imaginable.

Coincidentally the smartest person I know is also called Adam 😅 He hasn’t even graduated yet and is pretty much more influential than most of the smartest engineers at a 3000 empl. company (out of all those I’ve met, he’s the ”best”). He manages to revolutionize all the different areas he’s working on. One week he can be working on one area and the next he’s switched to another and after a few days he’s surpassed the engineers that’s been working on it for months. Immense mind.

Every skydiver knows that even when packing a same paracute in similarly looking way, sometimes it opens up slowly and sometimes with a yank which makes you hope you’d have lined the straps more carefully under you but and not where they can feel much more unconfortable. The point is that phenomena is more or less chaotic and it may be difficult to model all cornercases. For same reson, every change in details can alter behaviour.

Fluid Dynamics is incredibly difficult to model precisely, and even a small error blows the whole solution, and small eddies in air are incredibly difficult to measure let alone model.

We haven’t figured water flow out for modeling ships either. Fluid dynamics is a seriously difficult problem, and the computational power it takes to even start work on a model is huge. Work flows tend to start with how much computing time can I scavenge for this problem. Because CFD will eat up as much computing power as you can throw at it.

And people who look for a root cause can always find a wide range of things to pick and choose from. Why did the Beatles break up? Because they decided to start a band. What sank the Titanic? Neptune's law simply states that the captain caused it. It is always the captains fault. Reality never allows for a root cause, just a point of blame. We invented Captains, scapegoats and the Devil for a reason.

Yeah that’s not how a technical root cause works. Yes of course you can be childish and say “the thing broke because the universe exists and allowed the thing to be created” but that’s entirely not the point.

This isn’t a political exercise, the point is not to apportion blame but to identify, understand, and mitigate or remediate the problem.

Wow. nine downvotes. My record. No problem, but I ask if I that if I referenced how forensic data would be utilized at say...NASA or NAVSEASYSCOM, I would find agreement.
For those offended, I was not actually referencing this, nor any other specific use of the causality tree model, just the org level pitfalls when the data actually points to process issues... and everything can be seen as a process.

I know that the meeting space of industry and government, and especially the military branch of the govt, can make you sour and disillusioned pretty quickly. I hope you find some better experiences soon.

Ah, I see the source of the fan driven shade now. You see, my remarks were not referencing simple technical failure analysis. That, I suppose resulted in some defensiveness of SpaceX. I have the horrible habit of viewing things from a whole-system outlook. When anything or anyone is in a prejudiced position, and something goes wrong... well anything and everything they do or say WILL be used against them. There are those that experienced a bit of schadenfreude when D2 blew. Those folks don't need to be in the aerospace community to make trouble in the aerospace community.

Could the modifications have been done already (practically speaking) if nothing else shows up in the fault tree than what they've already found? In the same vein, is it likely the inflight abort vehicle is already at least mostly built? Also, they can make the IFA test double as a parachute test if they should need to, right?

I expect that the fault tree analysis report will be proprietary to SpaceX, ITAR restricted, or both. A FOIA request (at best) would probably only get you a clear title page with the rest massively redacted. Remember that NASA is purchasing a service, not a vehicle.

probably will but with anything SpaceX specific maybe being redacted, I do not know how much a NASA investigation has to respect corporate secrets. Its a tough call when you have a failure of a system related to a NASA program as NASA being a government agency they do have to weigh what should be hidden against the public's right to know.

The more I read about the Boeing situation, the more it looks like greed rather then incompetence: single fault prone probe, AOA indicators as an optional extra, no mention of MACS in training material to reduce type certification costs... hopefully the economic spanking will reduce nickle-and-diming for a while.

Won't change. FAA appears to have been "captured". They'll pretend to do the right things for now because of public scrutiny. Only hope is that the EU tells the FAA they no longer trust their certification.

Corporations are driven by fear and greed, just like the stock market. It was fear more than greed that drove Boeing's 737 MAX re-engining decision. Boeing saw Airbus taking a big chunk of the 737 market with their reengined A320.

Interesting how you left out that the MCAS failure mode is a failure that pilots have been trained to recognize and handle since the 1950s. And that the first MCAS incident, which hardly ever gets mentioned, the pilots DID recognize it, respond properly, and did not crash. The same airplane had the same failure the next day, and a different crew crashed. In the second crash, the first failure was an Airspeed Disagree just after liftoff, and MCAS was not yet even active since the flaps were still down. The pilots failed to even perform the two mandatory memory checklist items for the Airspeed Disagree, and drove the airplane deeper into trouble than they would have been if they had handled the first failure properly.

The human factors and training issues are as great as the design problems, IMO.

I will downvote you and give you a reply. Pilots train extensively for trim runaway. It is a known problem. This system wasn’t documented nor trained for. It wasn’t part of the type rating training or the recurrent training. And the recovery ultimately wasn’t as simple as it is with trim runaway. I fly a commercial airliner.

There is a reason when the MAX makes it back to the line that there will be unique sim training for this problem. Boeing, in my mind, wanted to keep the pilot training to a minimum that they (and their programmers) killed two planeloads of people.

And to make an upgrade package with the second sensor as well, gotta get that sweet luxury package money after all even if it means you sacrifice on safety.

I wonder if the airlines which purchased the upgraded macs system did so because of their usual purchasing polices, eg we always get the loaded version, or if someone was looking at the max very carefully and went "hey seems like this extra is more of a necessity."

AoA disagree was also an "optional" (costs extra) feature at the time, likely packaged together with the AoA gauge "optional" feature, so the pilots would not have even been aware of that particular failure at the time. Your comment about this being a failure mode that's been around since the '50's is also misleading. This particular MCAS presents itself very similarly to runaway stabilizer trim, but not identically. The subtle differences to a young crew who might not have had a lot of experience and certainly not as much experience as an American flagged crew, were clearly enough to result in the deaths of hundreds of people. Successfully making manual adjustments to stab trim would indicate that this was not a runaway stab trim failure which IIRC there was some evidence of the crew attempting that. Also, under every previous iteration of Boeing airplane, manually taking the stick or making other manual control adjustments would automatically disable just about any form of autopilot or other active computer flight control decisions.... until MCAS. This alone violations the principle of least astonishment and definitely warranted more communication and training regarding the feature.

Hang on a second: A digital flight control aid system in the 1950s? Really? They were flying on vacuume spun gyros back then.

Pilots recognized a fault in a system they didn't know because it wasnt in the manual or training? No they didn't they recognized that it was some autopilot thing and mushed the red "master disconnect" button. Which as it happens was the right call.

I grant they didnt respond to airspeed disagree, probably because they were to busy trying not to die to notice the left speedo and right speedo didnt read the same. And if they did they may not have made the connection, because again they weren't told how the system worked.

Electrical trim runaway has been trained for since the 1950s. It doesn't matter if it is a short circuit, a failed switch, or a stuck relay, or confused software, it is still trim runaway. Every pilot is supposed to sim handling it on a regular basis. The 737MAX is not fly by wire. The 737MAX still uses cables and pulleys and hydraulics for everything except the spoilers.

probably because they were to busy trying not to die to notice the left speedo and right speedo didnt read the same.

THEY TRAIN FOR THAT EXACT FAILURE. The airplane TELLS THEM the two disagree, and when that happens, they have just two things to do, that they are supposed to remember without looking up. Set the power, and set the pitch. Those two actions ensure they will continue flying. And they failed to do them. And if they had done them, they wouldn't have driven the airplane into an environment where it was difficult to manually change the trim.

I think you have hit on one of the fundamental problems here. The max is, as you state, not a fly by wire architecture, yet the MCAS system is an attempt to introduce a fly by wire envelope modification function without having to recertify as a new aircraft.
However in itself this is a response to the aircraft's aerodynamic characteristics. In a wind up turn, the stick force per gee reduces, which is the exact opposite of how you are supposed to design an aircraft ( if I am remembering my aircraft design course properly).

I need to go back and do some more research, but the fact that EASA are demanding flight testing with MCAS off makes me think we won't see the max flying in Europe for a good while yet. There's a summary in the Seattle Times

This is not just electric trim. This is a hidden automatic autopilot feature that is a digital bandage to compensate for undesirable flight characteristics induced by an unbalanced design. Ironicly in the 1950s this design would have been simply rejected for being unstable.

More than once I have noticed that if a system sucks and produces lots of error (ex. 1 in 100) than operators tend to be diligent about checking for and dealing with those errors, the output tends to be error free. If the system improves so it produces little error (ex. 1 in 100,000) then the operators start to trust the system and stop checking for those errors and forget how to deal with them, so the output can actually become worse.

So yes it is a combination of technical issues and lack of training for crews. However the point of the max as I understand it is to allow crews to fly it with minimal new training while the aircraft itself has a major change in engines and balance, the technology is supposed to account for those changes. It all comes down to Boeing trying to cut both their costs and the cost to operate the aircraft for the airlines.

If the system improves so it produces little error (ex. 1 in 100,000) then the operators start to trust the system and stop checking for those errors and forget how to deal with them, so the output can actually become worse.

Which is why airline pilots must spend time in a simulator with an instructor handling faults every six months. Most never see a real world crisis. Recurrent training is essential, and they are supposed to receive it regularly. Trim runaway training is common enough there is at least one video on youtube showing how to handle in on 737 Classic by real instructors in a real simulator, not MS Flight Sim.

Still. The actual symptom was that the trim was being automatically adjusted badly. And the MEMORY PROCEDURE to handle that problem is and was to flip the two switches to turn off the affected automatic trim adjustments. Which was successfully followed on the day before the first crash at the suggestion of the off duty pilot in the jump seat in the cockpit.

Yes, the MCAS added a new way to trigger runaway trim. But the procedure to handle the runaway trim did not change and was not followed on the two fatal crashes.

Yes the design of that system was sub-par in multiple areas. But I don't think those two flights should have ended in fatalities. A little off topic but there's my rant. Carry on.

We don't yet know exactly what happened in the Lion Air and Ethiopian Airlines crashes, but you are grossly oversimplifying the procedure for runaway trim at takeoff.

The procedure for a runaway trim is not to flip a switch to disable automatic trim adjustments. No such switch exists. The procedure is to flip a switch to cut power to the trim system. After this, trim can be controlled by manually turning a large trim wheel which is mechanically connected to the elevator.

However, with the aircraft in a nose down trim, and at relatively high speed, the aerodynamic forces on the stabilizer are great enough that a single pilot may not be physically capable of manually adjusting the trim. Note also that during the accident, because of the faulty AoA data, the stick shaker was activated. The aircraft is warning of a stall, and the pilots have takeoff thrust set.

The pilots of Ethiopian 302 did cut off the trim system, but they did it with the trim in a nose down position, and it seems they could not adjust the trim, because we know they reenabled the system moments later, causing MCAS to activate again and push the nose down further.

It seems the pilots did follow Boeing's procedure, but could not regain control of the aircraft. The accident may have been avoidable if the pilots reduced thrust and allowed MCAS to complete a cycle and cut off power when the trim was in a neutral position. But all of this was happening a thousand feet off the ground, with a stick shaker activated, and with an undocumented bit of software pushing the nose down without cause.

I prefer to think that the primary cause of this accident was a freakin’ singly-redundant flight control system capable of driving the plane into the ground in a matter of seconds. Every person who worked on the design changes to MCAS which gave it this power (after it had already been approved to be single redundant assuming it would not have the power to drive the plane into the ground) should be flogged for not having two brain cells to speak up or blow a whistle.

Even without MCAS, why do planes still have doubly-redundant (let alone single) critical sensors and computers? Multiple crashes have been attributed to a single sensor failing, and the pilots failing to identify which sensor was correct, and losing situational awareness. Three sensors allow the computer to automatically identify the failure through voting.

SpaceX, Space Shuttle, etc. have known these lessons for decades. The Space Shuttle had quintuply-redundant voting flight computers, and a backup computer written in a completely different language (at least doubling the cost of development)...and there were only seven, let alone 200, lives at risk.

I can’t believe people are still pushing the just flip two switches myth. Just flipping two switches results in the plane being stuck in a nose down configuration, which pilots haven’t been trained to correct in decades, and which the Ethiopian Airlines flight probably didn’t have enough altitude to correct even if they had known the procedure that was removed from the manuals decades before.

The actual correct way to have saved the plane would have been to put the flaps back down, as that would disable MCAS without shutting down power to the trim motors, but the pilots hadn’t even been told that MCAS existed, never mind trained in exactly what circumstances it did or did not activate and how to deal with it if it went crazy.

Boeing lied to the FAA about how much control authority MCAS had, and they either hid or lied about the fact that the plane was so aerodynamically unstable that MCAS needed that authority. All the blame for both crashes falls squarely onto Boeing and the planes they built, which is why those planes are all still grounded and will continue to be grounded for months to come.

I know this is severely off topic, but the quality issues Boeing commercial aircraft have suffered over the last decade really makes me hope that the 737 Max disaster forces Boeing out of the passenger aircraft market, they're clearly not good enough for it. They appear to be an okay military contractor though (except for their tankers)

Um... dude. The switch flipping is not a myth. It's a documented, current procedure. And it works.

The fact is that the day before that first aircraft had its fatal crash, the same runaway trim issue happened. And flipping those switches (as documented) worked. I presume when they flipped the switches, they were trimmed relatively OK (or that they could use the manual wheels to adjust the trim).

But then, then those pilots made what will probably be looked upon as a poor decision to continue their flight to their destination with the auto trim disabled rather than to return and land immediately. And then, even worse, the airline decided to fly that plane again the next day!!! They made an overnight attempt to fix/change something and did not do any test flight. And then the fatal flight happened. THAT is pretty unbelievable.

On the fatal flight, the pilots used the manual trim switch to "correct" the bad trim inputs that MCAS was issuing. This let them get back in trim (for a bit). Their use of the manual trim told MCAS to leave its grubby mitts off of the trim for the next 5 or so seconds. And those pilots flew the plane for something like 5 minutes, manually correcting the trim every 10 or 15 seconds or so when MCAS did its bad trim adjustments again and again and again. They had ample opportunity to recognize a runaway auto trim. How could you NOT recognize that you were getting runaway trim adjustments with what they were seeing? They could have flipped those switches during one of the many times they were properly trimmed. Yes, there was a lot going on in that cockpit. Lot's of alarms and stuff. But they didn't follow that procedure.

Boeing did some very bad stuff here as you stated (MCAS had too much control authority, etc.). And Boeing is far from blameless on this. And the plane is properly grounded until this gets resolved.

In my opinion, though, the airline gets some significant blame here for flying that plane after the previous incidents. And it may be that the pilot training on disabling the autotrim was insufficient. Remember, "autotrim disabling" existed when autotrim was invented - eons before MCAS was added... auto-anything can fail and may need to be disabled. And a pilot needs to know how to do that. That's why it's a memory procedure.

BUT, my main premise is/was this: Those planes should NOT have crashed. If you're gonna be a pilot, you damn better well know how your plane works... and you need to know all the procedures. Otherwise, I sure as heck don't wanna be on a plane being flown by that crew.

They should have been able to land the plane (like the day before). And the pilots should have then given the airline HELL for putting that plane back in service. And then Boeing should have been given hell for how MCAS was working. But the plane shouldn't have crashed and people shouldn't have died.

This, is a SpaceX reddit, though... so let's go back to SpaceX stuff. :-)

MCAS was put in the system because the 737MAX stall characteristics are different than the planes those pilots had type ratings for. Therefore, turning MCAS off means they were not certified to fly it!

Boeing is grossly oversimplifying this whole point because otherwise their single biggest argument for selling the MAX is non-existent.

There were statements all over the place that they followed procedure. Misplaced attempts of blaming the pilots don't help that. Making statements that under stress they forgot procedure is just a way of blaming them.

the problem is THERE WAS NO PROCEDURE! there was no mention of MCAS anywhere in their training manuals. boeing did this specifically to cut down on the cost of re-training/certifying all the pilots.
this is 100% boeing fault.

I think I read that SpaceX already static fired the booster for the crew mission? It is still months away at the earliest. Is it because it was just the next booster off of the assembly line, and no upcoming missions require a new booster? Do they have a stockpile of flown boosters on hand for any upcoming missions?

"Work" does not necessarily mean design changes. Some of it could be analysis to better understand them, and some could involve process changes such as additional inspections and tests that do not change the end result but make it more reliable.

I think copv's have been a lingering concern ever since Amos 6, I'm sure they want them to be double bullet proof since they have been a known failure point in the past. Having copv's inside of tanks is pretty new so I'm sure there's tons of room for improvement, especially with the focus they have gotten since Amos

You're right about NASA and the COPVs. NASA was lured into a false sense of security for over 20 years of Space Shuttle operations during which the space agency tried unsuccessfully to solve the foam detachment problem on the External Tank.

Foam debris was falling off the ET since the first Shuttle flight in April 1981 and impacting on the Orbiter thermal protection system tiles and on the reusable carbon-carbon (RCC) nose cap and wing leading edges.

The COPVs, like the Orbiter TPS, are Criticality 1 items--components which when they fail can cause loss of crew and vehicle and which are not redundant, i.e. have no backup. NASA's luck ran out on flight #113 when foam hit an RCC panel on the left wing of Columbia, punched a square foot hole, and eventually caused the Orbiter to disintegrate during the EDL over Texas.

Slight changes are always being made to flight hardware to make it more reliable and safer, I'd expect tons of research has been going on since Amos 6 and they are still finding ways to make the tanks better, even though they have already been made "safe"

I wouldn’t think of it that way. Think of it as having to fill in a bunch of correlations. You can know exactly what happened but you still have to go through how everything is connected. They already “know” what happened - the pressurized slugs - but the rest of the tree needs to be filled in too. So they can already have corrected that problem in theory while still finishing the tree, which could show nothing else is wrong. They don’t have to wait until it is done to start work.

Considering how many problems they've had with them and NASA not being interested in re-used boosters or capsules at all (and the gain in performance from running full expendable), it might be worth spending a little mass budget and ditching COPV altogether in favor of more durable, more traditional options.

Op is getting downvoted for making the statement that NASA has no interest in reusing dragons and that they should ditch copvs because of that. Meanwhile spacex just flew their third mission with the same dragon capsule to the space station.

Person who replied to person who replied to op is probably getting downvoted by people who think it’s the same person as op.

Downvotes are happening because the OP used a sweeping inaccurate statement: "NASA not being interested in re-used boosters or capsules at all " His follow on insult about cultists implies it was probably intentional.

This is BS. Boeing offered and got money for the studies on the reusability of the Starliner. More of it they plan to start reusing capsules from "the day one".

More of it as Teslarati states

" peaking at the most recent (August 27) NASA Advisory Council meeting, Lueders specifically stated that SpaceX had proposed “a new vehicle every time for [NASA]”, although NASA specifically provided the option for either new or reflown hardware, similar to Commercial Cargo where SpaceX already routinely reflies both Falcon 9s and Cargo Dragons on official NASA resupply missions. "

I repeat again: not only NASA is interested in re-flying crew capsules, they offered project money to cover re-usability development. SpaceX wasn't interested. As it is easy to see their interests lie elsewhere, and extensive Dragon 2 development and improvement is not in their plans.

Oh god i really tried to couch my posts to keep the spacex cultists happy. Nasa as far as i can tell has told SpaceX as part of their contract they only want to fly astronauts on new capsules, and that afterwards these capsules will be reused only for cargo missions.

Originally NASA specified new Dragon 1 and boosters for every flight but now they are more amenable to reuse. Possible they will come round to reusing Dragon 2 and boosters on crew flights, following certification process.

That’s incorrect. Cargo Dragon 2 will be a different spacecraft, not a reused Crew. And NASA are open to Crew Dragon flying multiple missions if SpaceX choose to pursue that. SpaceX have not chosen to pursue that yet. I expect they will after they start flying them. They will then have to certify them for reuse in collaboration with NASA. Boeing have pursued this from the start. It was SpaceX’s choice not to.

Nasa as far as i can tell has told SpaceX as part of their contract they only want to fly astronauts on new capsules

Who told you it was NASA rather than SpaceX not being interested in certify Crew Dragon for reuse from the beginning? NASA is not against reuse of capsules for crewed missions, Starliner is being certified for at least 10 reuses.

Most probably to save some time certifying extra things that they really didn't need to fly people. They know the more they try to do, the more tests and paperwork and things like that they will have to do so if you remove something that's some time you're saving off the schedule

They don't require these spacecraft to be reusable or not, that's not on the specifications of the contract. But if the provider wants to do that they must certify that and that takes time and money. Same happened with land landings using retropropulsion. They don't say "No! We don't like this so we're not allowing this!". They just say "ok, you just have to make sure it is safe and for that you need to bring us this loong list of things we want you check". Same happened with load and go. While media and some others (with very well defined interests) were saying "NASA will never approve this!!", NASA and SpaceX were working together to make it happen safely and understand the proccess.

I don't know where the thought of the capsules being totally ruined after splashdown came from. From all they've said they actually got very good at avoiding sea salt intrusion and will be able to reuse Cargo Dragon 2 up to 5 times thanks to that. I mean, it's not that it's totally ruined, it's just that it is really not worth the try certify that for crew due to the extra conditions imposed just due to the fact that there are humans on board.

I think there may be a language barrier here. I believe what they are saying is that NASA will not reuse boosters for crewed missions which I think is correct.I believe they will reuse dragon 2 for crewed missions (see edit) Obviously they will reuse boosters and dragon 2 for cargo missions.

Edit:
So I did some digging and found here that each crewed mission will be all new hardware. It states that NASA gave SpaceX the option to reuse but they chose not to.

As I'm sure you well know, running two parallel versions of the booster and stage 2 would add significant cost to Spacex, so they will do everything possible to coax NASA into using the same boosters as they use elsewhere. So it makes no sense to simply "use traditional methods" in this case if they feel they will get the end result in time.

OP's comment said NASA has "NASA not being interested in re-used boosters or capsules at all" which was poorly phrased at least and perhaps intentionally misleading, and in any case that exact same mentality was also true for cargo, originally. But over time NASA saw that there was no increased practical risk and adjusted their thinking.

Knowledge is not a democracy. I didnt say i dont place value in a community, i said i dont give a fuck about downvotes. Especially when i've noticed a cult like pattern of "dissent is harassment, elon-god cannot be questioned"

Knowledge is not saying "NASA doesn't use reused booster" when they do for cargo missions. You failed at your own definition of knowledge. And you started acting like a dick immediately after that. If any community accepts such behavior, it's a pretty bad community. And nobody, not even you, questioned anything regarding Elon. You simply stated something that wasn't true.

The subreddit has had issues of overmoderation in my opinion, one that at least the mods seem to be aware of and have had conversations with the user-base about. However, I do not feel your comment is an example of overmoderation, but of appropriate moderation.

Everything the mod said is exactly the way I (and apparently others) read your comment and your responses appear to demonstrate you see no error in your manner of conversation.

Considering that many people in the thread went to look for evidence and then discussed it in a level headed manner goes to show how unwarranted your responses were.